| In this paper,mainly aiming at the problems that understory notoginseng seedling trench still relies on manual use of small tooth rake to open the trench,low efficiency,high labor intensity and difficult to guarantee the quality of the trench,based on the analysis of the working principle and characteristics of the existing trenching machines at home and abroad,combined with the agronomic parameters of understory notoginseng planting,the design of the trenching parts suitable for the transplantation of notoginseng seedlings.Simulation analysis and experimental research are carried out.The main research contents and conclusions of this paper are as follows:(1)The relevant agronomic technical requirements were analyzed,and combined with the actual investigation situation,the planting mode of understory panax Notoginseng seedlings transplanting and the relevant parameters required for the ditching of transplanting seedlings were determined.Soil samples were collected at the base of Panax Notoginseng transplanting under the forest,and the moisture content,density,firmness,Angle of reactivity and Angle of sliding friction of the soil were measured.(2)The characteristics,advantages and disadvantages of different types of ditching parts were analyzed,and the types of ditching parts were determined.Combined with the main influencing parameters such as the cutting edge curve of the existing three types of ditching parts,the optimization design calculation was carried out,which has met the agronomic requirements of panax notoginseng transplanting ditching under the forest.The cutting edge curve of sliding knife type is determined to be y=ax~2,the radius of disk is 260 mm,the number of notches is 13,and the cutting edge curve of boot type is y=ax~2+bx.(3)At the same time,ANSYS was used to carry out static analysis.After grid division,load and constraint were applied and then simulation was carried out.Due to the shallow ditching depth,only about 40 mm,the maximum stress of the three ditching components was 2.406 MPa and the maximum deformation was 1.43E-04 mm,which proved that the ditching components had sufficient strength and stiffness.Able to withstand stress and deformation in the working process.(4)Three-dimensional software was used to draw the model of ditching parts,and discrete element simulation software EDEM was used to conduct simulation experiments to study the soil return amount,ditching depth and depth stability of ditching parts with different types,speeds and squeezing angles when working under forest conditions.The experiment concluded that the maximum working resistance of the three ditching parts was 88 N.Through the variance analysis of the results,It is found that the speed factor has the most significant influence on the trenching effect index,followed by the squeezing Angle factor,and finally the type factor.The best parameter combination of sliding knife ditching parts,forward speed of 6km/h and extrusion Angle of 45° was determined by intuitive analysis method,which could meet the requirements of national standard GB/T41552 and the standard of seedling transplanting ditch.(5)Two groups of single-factor soil tank tests were carried out according to the optimal parameter combination determined by the simulation experiment results.The test results were consistent with the simulation orthogonal experiment results,which verified that the design was reasonable and could achieve the expected effect.The experimental results show that the velocity factor has a significant influence on the source of error(F=9.831,P<0.013),and the optimum forward velocity is 6km/h,while the extruding Angle factor has a very significant influence on the experimental soil return amount(F=9.831,P<0.07),and the optimum extruding Angle is 45°.This study is of great significance for improving seedling transplanting efficiency and reducing cost of understory panax notoginseng... |
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